Extract the Linux serial number without sudo

Question

It is possible to extract the Linux serial number without using sudo?

I know it is possible to do in Windows: wmic bios get serialnumber and in macOS: system_profiler | grep "r (system)". Both of them do not require root privileges.

In Linux this can be used: sudo dmidecode -s system-serial-number, but it needs sudo. Is there another way?

Answer 1

dmidecode reads this information from physical memory, using /dev/mem, which requires root.

The same information is also provided by the Linux kernel via sysfs in a virtual directory, /sys/devices/virtual/dmi/id.

Unfortunately, someone decided that all information in that virtual directory is open to anyone for reading, just not the serial numbers:

$ ls -l /sys/devices/virtual/dmi/id

-r--r--r-- 1 root root 4096 Nov 25 17:12 bios_date
-r--r--r-- 1 root root 4096 Nov 14 14:59 bios_vendor
-r--r--r-- 1 root root 4096 Nov 25 17:12 bios_version
-r--r--r-- 1 root root 4096 Nov 25 17:12 board_asset_tag
-r--r--r-- 1 root root 4096 Nov 25 17:12 board_name
-r-------- 1 root root 4096 Nov 25 17:12 board_serial
-r--r--r-- 1 root root 4096 Nov 14 14:59 board_vendor
-r--r--r-- 1 root root 4096 Nov 25 17:12 board_version
-r--r--r-- 1 root root 4096 Nov 25 17:12 chassis_asset_tag
-r-------- 1 root root 4096 Nov 25 17:12 chassis_serial
-r--r--r-- 1 root root 4096 Nov 25 17:12 chassis_type
-r--r--r-- 1 root root 4096 Nov 25 17:12 chassis_vendor
-r--r--r-- 1 root root 4096 Nov 25 17:12 chassis_version
-r--r--r-- 1 root root 4096 Nov 25 17:12 modalias
drwxr-xr-x 2 root root    0 Nov 25 17:12 power
-r--r--r-- 1 root root 4096 Nov 14 14:59 product_name
-r-------- 1 root root 4096 Nov 25 17:12 product_serial
-r-------- 1 root root 4096 Nov 14 14:59 product_uuid
-r--r--r-- 1 root root 4096 Nov 14 14:59 product_version
lrwxrwxrwx 1 root root    0 Nov 14 14:59 subsystem -> ../../../../class/dmi
-r--r--r-- 1 root root 4096 Nov 14 14:59 sys_vendor
-rw-r--r-- 1 root root 4096 Nov 14 14:59 uevent

If you can install package hal (not installed by default on recent Ubuntu versions), this command will work for you as non-root:

 lshal | grep system.hardware.serial

 system.hardware.serial = '<serial_number>'  (string)

This works because package hal installs the hald daemon, which runs as root and collects this data, making it possible for lshal to read it as non-root.

Answer 2

Another solution which does not require root privileges:

udevadm info --query=all --name=/dev/sda | grep ID_SERIAL

This is actually the library that lsblk, mentioned by don_crissti, leverages, but my version of lsblk does not include the option for serial.

Answer 3

Device1 name and corresponding serial number:

lsblk --nodeps -o name,serial

Output:

NAME SERIAL
sda  0000000012400917BA30
sdb  0000000012400917BA96

Add -n if you don't want to print the header line:

lsblk --nodeps -no name,serial

Output:

sda  0000000012400917BA30
sdb  0000000012400917BA96

Pass the device as an argument to get only the serial number of a specific device:

lsblk --nodeps -no serial /dev/sda

Output:

0000000012400917BA30

Keep in mind lsblk lists information about all available (or the specified) block devices. Now, for those who do not know what that last term means:

In general, block devices are devices that store or hold data. Diskette drives, hard drives and CD-ROM drives are all block devices. But that's not a problem when using lsblk as you can simply add more columns, e.g., type (device type) and/or tran (device transport type), etc.:

lsblk --nodeps -no name,serial,type,tran

.

sda  0000000012400917BA30     disk sata
sdb  0000000012400917BA96     disk sata
sr0  4B583242334C453233353320 rom  usb